We run into Lollapalooza creator and Jane's Addiction frontman Perry Farrell at the dubstep tent. He gave us a high five.

Thousands descended upon Grant Park in Chicago on the first day -- and the 20th anniversary -- of Perry Farrell's Lollapalooza. In this slideshow: Perry himself walking the fest (he's a Skrillex fan); Muse, White Lies, Bloody Beetroots, and much more. PHOTOS BY DENIS JEONG PLASTER on Friday, August 5, 2011